Cas12a Base Editors Induce Efficient and Specific Editing with Low DNA Damage Response PMID: 32492431

Target-related Cytokines

2026-09-23

Cas12a Base Editors Induce Efficient and Specific Editing with Low DNA Damage Response

Cell Rep. 2020 Jun 2;31(9):107723. doi: 10.1016/j.celrep.2020.107723.

Xiao Wang ¹ , Chengfeng Ding ¹ , Wenxia Yu ¹ , Ying Wang ² , Siting He ³ , Bei Yang ⁴ , Yi-Chun Xiong ² , Jia Wei ² , Jifang Li ¹ , Jiayi Liang ¹ , Zongyang Lu ¹ , Wei Zhu ⁵ , Jing Wu ⁵ , Zhi Zhou ⁵ , Xingxu Huang ⁶ , Zhen Liu ⁷ , Li Yang ⁸ , Jia Chen ⁹

Affiliations

1. School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; Shanghai Institute of Biochemistry and Cell Biology, CAS Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, China; University of Chinese Academy of Sciences, Beijing 100049, China.
2. CAS Key Laboratory of Computational Biology, CAS-MPG Partner Institute for Computational Biology, Shanghai Institute of Nutrition and Health, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China.
3. University of Chinese Academy of Sciences, Beijing 100049, China; Institute of Neuroscience, CAS Key Laboratory of Primate Neurobiology, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China.
4. Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, Shanghai 201210, China.
5. School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China.
6. School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; Shanghai Institute of Biochemistry and Cell Biology, CAS Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, China.
7. Institute of Neuroscience, CAS Key Laboratory of Primate Neurobiology, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China. Electronic address: [email protected].
8. CAS Key Laboratory of Computational Biology, CAS-MPG Partner Institute for Computational Biology, Shanghai Institute of Nutrition and Health, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China. Electronic address: [email protected].
9. School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; Shanghai Institute of Biochemistry and Cell Biology, CAS Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai 200031, China. Electronic address: [email protected].

Abstract

The advent of base editors (BEs) holds great potential for correcting pathogenic-related point mutations to treat relevant diseases. However, Cas9 nickase (nCas9)-derived BEs lead to DNA double-strand breaks, which can trigger unwanted DNA damage response (DDR). Here, we show that the original version of catalytically dead Cas12a (dCas12a)-conjugated BEs induce a basal level of DNA breaks and minimally activate DDR proteins, including H2AX, ATM, ATR, and p53. By fusing dCas12a with engineered human Apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like 3A (APOBEC3A), we further develop the BEACON (base editing induced by human APOBEC3A and Cas12a without DNA break) system to achieve enhanced deamination efficiency and editing specificity. Efficient C-to-T editing is achieved by BEACON in mammalian cells at levels comparable to AncBE4max, with only low levels of DDR and minimal RNA off-target mutations. Importantly, BEACON induces in vivo base editing in mouse embryos, and targeted C-to-T conversions are detected in F0 mice.